JPS59200531A - Dual switching system - Google Patents

Abstract

PURPOSE:To secure the continuation of processing by holding fixed data predetermined in a device to be controlled, and specifying the operation of the controlled system on the basis of the fixed data during stand-by/in-use switching. CONSTITUTION:The control data of a controller 1 is transmitted to the device 3 to be controlled through a switching circuit 5 and processed by a processing circuit 6, and the device is included in an in-use system. When the switching of the device to be controlled is required owing to a fault, etc., of the device 3, a switching control circuit 4 operates the circuit 5, and disconnects the device 3 from the in-use system to connect a fixed data circuit 7' to a processing circuit 6'. This state is maintained until the circuit 6' receives processing data from the controller 1, and the control operation of a stand-by device 3' to be controlled is determined by the data of the circuit 7' during said period. For this purpose, the contents of the fixed data are selected properly to carry on the operation of the controlled device which is required as a system during the switching operation period although it is limited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a duplex switching method that makes it possible to minimize system failures due to duplex switching operations in a duplex controlled device.

Conventionally, for this type of duplicated controlled device 2,
In order to ensure continuity of processing, each control is performed independently from the control device 1 as shown in FIG. 1 without going through a switching circuit, or alternatively, the switching circuit is controlled independently as shown in FIG. 2 at the expense of continuity of processing. It was connected to the control device 1 via 5. However, in the case of FIG. 1, the output circuit of the control device is complicated, and when the distance between the control device 1 and the controlled device 2 is large, the cost of connecting wires between them increases. Furthermore, in the case of FIG. 2, there is a drawback that the operation of the controlled device 2 stops if an abnormality is discovered in the control device (including abnormalities in connection lines and switching circuits) during the operating period of the switching circuit 5 or after switching. Ta.

In the case where the control data from the control device related to the minimum required functions of the controlled device can be determined in advance, the present invention incorporates fixed data corresponding to the control data in the controlled device, and operates the switching circuit. To provide a redundant switching method that enables continuous processing of a controlled device using fixed data when it is found that control data cannot be received from a control device during or after switching. It is.

In other words, in the present invention, two
The controlled device has fixed data that is used as a substitute for control data inside the controlled device, and if the control data is not transmitted from the control device during the switching operation of the switching circuit or after the switching operation is completed, the fixed data is used as a substitute for control data. Therefore, the controlled device continues to operate.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 3, the control data of the control device 1 is transferred to the switching circuit 5.
The signal is then transmitted to the controlled device 3 and processed by the processing circuit 6, so that the controlled device 3 is used as the active system. Controlled device 3
When it becomes necessary to switch the controlled device due to a failure, etc., the switching circuit 5 is activated by the operation of the switching control circuit 4, the controlled device 3 is disconnected from the current system, and the fixed data circuit 7' is switched to the processing circuit 6'. Connected. This state continues until the operation of the switching circuit 5 is completed and the control data from the control device 1 is received by the processing section 6'. In this state, the control operation of the controlled device 3' is determined by the data of the fixed data circuit. Therefore, by appropriately selecting the data content of the fixed data circuit, even if control data cannot be received correctly during the switching operation period or after the switching operation is completed, the operation of the controlled device required by the system can be continued, albeit in a limited manner. becomes possible.

As explained above, the present invention retains predetermined fixed data inside the controlled device, and stores the fixed data during the operation period of the switching circuit and until normal control data is received from the control device after the switching operation is completed. By defining the operation of the controlled device depending on the content, there is an effect of ensuring continuity of processing, albeit within a limited range.

[Brief explanation of drawings]

1 and 2 are diagrams showing conventional examples, with FIG. 1 showing a duplex system without a switching circuit, and FIG. 2 showing a duplex system including a switching circuit. FIG. 3 is a configuration diagram of a duplex system according to an embodiment of the present invention. In the figure, 1...control device, 2, 3.3
'... Controlled device, 4... Switching control circuit, Death... Switching circuit, 6.6'... Processing circuit, 7.7'... ...Fixed data circuit. 5-

Claims (1)

[Claims] In a duplex switching method for a system consisting of one control device and two identical controlled devices that operate based on control data transmitted from the control device via a switching circuit, during the operating period of the switching circuit. and a redundant switching system, characterized in that, if an abnormality in the control device is found after switching, the controlled device operates according to predetermined fixed data stored in the controlled device.